Oyster brood collecting grills are already known, for example from French Pat. No. 1,360,273. These grills are generally plane grills with suitably spaced parallel bars. The oyster brood which is fixed to the bars is gathered by means of blades in which grooves are provided which correspond to the bars of the grill and are displaced longitudinally in respect of these bars to loosen the brood. This method necessitates the disassembly of the grill units, then its reassembly prior to re-use when the brood has been gathered. Although these operations can now be achieved in a largely mechanical manner, they nevertheless remain long and tedious, and consequently impair the efficiency gained by using such grills.
It also has been proposed to detach the oyster brood from the collectors by subjecting the latter to impacts. Another problem then arises. The collectors of oyster brood are covered with a lime coating, with a thickness of the order of 1 mm, on which the young oysters become fixed. When the collectors are subjected to an impact, the coating and the oyster brood become detached from the collectors in sections of variable dimensions, some of these sections often comprising several oysters. In such close proximity, the development of the oysters is hindered, and their capacity to breed is endangered. The present invention overcomes these difficulties.